One of the best things about fighting today is that it's fairly free of bullshit. The sport is beneath the notice of the big-time mythmakers, and its own media hustlers are too inept for their godding up to have any real effect, so a fight is rarely about anything so simple as redemption or salvation or whatever exactly major football games are supposed to be about. It is, usually, just about two athletes trying to do something difficult well.

This is especially true of the flyweights, 125-pound fighters so fast that what they're doing can be hard to see. John Dodson will challenge Demetrious "Mighty Mouse" Johnson for the division title this Saturday at the United Center in Chicago, with the bout being broadcast on Fox, and there is no line involved here past the prospect of a scrap between the best and second-best in the world at their size. This narrative austerity is probably too much even for fight fans. After Dodson held an open workout Wednesday in which he threw straight-up flying ninja kicks at a target taller than he is, half the questions from the assembled press centered on the issue of why no one really cares.

"It's because they heard the 5'3" part," he said. "Every guy that comes into the bar and gets drunk, they're like, ‘I need someone to beat up! Midget, you ready to go?'"

There may be something to this, but the better answer, which he came around to, is: So what? Johnson vs. Dodson is the kind of bout that could make someone who thinks fighting is stupid and pointless reconsider his position. It's less a fight than a surface phenomenon: lines refracting off lines and demonstrations of half-remembered laws of physics involving the conservation of something or other. If someone doesn't care about that—or a lot of someones, as indicated by the jeering crowds of morons at some recent flyweight fights—what's it to the rest of us who do? The thing is still there to be enjoyed.

The whole appeal of a fight like this is, in theory, speed. Johnson is the fastest fighter in the world by acclamation, and the distance between him and Dodson is too small for any normal person to detect it. I was talking to a guy involved with promoting the fight who figures that there will be more mixed martial arts in one round of this than there would be in three of a heavyweight fight, and that seems actually true; watching their fights, you can get worn down just trying to track what's going on. Two years ago, for instance, when Johnson fought Miguel Angel Torres, a very tough bantamweight with freakishly long arms and a brutal ground game, you could have scored rounds for him based only on his escapes from trouble. Torres would buck him around with his hips, sweep him and tie him up in submissions, and every time Johnson would thwart him, collaring, clinching, and slipping in a jab or an elbow in the midst of every transition from one position to another, then moving in to pepper him with more shots. Trying to tell just how he did it, or how many shots he threw in one of his blurrier combinations, is exhausting—and that was hardly one of his faster fights.

"It's going to be a hard fight to watch in some senses," says Greg Jackson, Dodson's trainer, "because we're going to have to fight for little things during the fight, and those little things might be hard to see, because it's going to be going at 190 miles an hour."

By Jackson's read, the two are pretty well matched. The champion is exceptional at changing levels and planes with his striking and at exiting after landing a hit; he's a strong wrestler; and he's very precise with his angles. He never leaves himself squared up to his opponent, which makes him incredibly hard to hit, and if you do land one, he tends to shrug it off. Because of all that, and because he has naturally light hands and a slightly sketchy offensive-submission game, he has the second-longest average fight time in UFC history. This and Johnson's drab persona—"Just go and do my thing, man," is his response when asked to give a scouting report on himself—likely have to bit to do with the sour crowds.

Dodson is a similar fighter, but, in his way, an even freakier athlete. There are the dunks and standing backflips that dumb reporters ask him to do on command, but he can also move the lower half of his body out of the way of a checked kick without moving the top half at all and land leaping kicks after running up the cage, and he relies less on head movement at times than on flat-out ducking punches. Like Johnson, he's very smart—Dodson mimics other fighters for the benefit of teammates, picking off bits and pieces of their games in the process—and you can tell it both in what he does, like the way he can control the pace of a fight with his footwork, and in what he says, like the way he scoffs at inside-fight talk about intricate strategies and game plans as so much nonsense.

"When any fighter has to start thinking about more than two things," he says, "they're done."

He also has heavy hands, which are rare in the division, and he has won two of his last three fights by knockout, one with a counter as his opponent was coming in on him. Jackson dismisses any idea that he'll be out there sitting on his punches—"The problem with Demetrious is if you just stand still, he'll hit you and exit before you can act"—but Dodson can clock anyone.

That matters, even if it shouldn't, because if no one cares about the flyweights, that probably has less to do with their size than with how long their fights go and how rarely they end in a knockout. (There is a generally inverse relationship between the size of the fighters and how often they finish a fight; there is a direct one between the size of the fighters and the size of the purse.) Either Johnson or Dodson could grind the other one into a fine powder with wrestling and jiu-jitsu on Saturday, and it wouldn't satisfy the baying masses anywhere near as much as would one light fluke shot leading to a chance referee stoppage. A smart fight person I know insists that the public's desire for finishes has less to do with bloodlust than with wanting some visual proof that one fighter was able to break the other one—the logic of the money shot—but whatever the cause, it amounts to a good sport having a bad audience.

Two nights ahead of the fight, I ran into the great bantamweight champion Dominick Cruz at a bar. (One of the best things about fighting is that you can run into great champions at bars.) He's fought Johnson, and he figures that the fight will be five rounds of swinging at nothing, which he means as a real compliment, since Cruz's own style recalls that of Willie Pep, the boxer who supposedly won a round without throwing a punch. He didn't think the crowds would like it, remembering the days when smaller fighters were first brought under the UFC's promotional umbrella and fans would tell them they weren't good enough to be in the UFC.

"Really?" I asked.

"You wouldn't believe fans," he said.

Even if the jeers come down, two men who between them weigh less than a tight end throwing switches, feinting against feints, running combinations that only make any sense in slow motion, and generally showing the full complexity of what can happen in a fight will make an excellent counter to sporting nonsense and competitive hagiography. They go and do their thing; one wins, and one loses. There's nothing more to it.

Tim Marchman has written about fights for the Wall Street Journal, Sports Illustrated, Slate, and The Classical; despite this, you're right, he has no idea what he's on about. Feel free to tell him @timmarchman.